[PATCH][gdb/symtab] Find filename in shared psymtab

[Tom de Vries]

On 08-04-2020 13:03, Tom de Vries wrote:
> Hi,
> 
> When running test-case gdb.ada/dgopt.exp with target board
> unix/-flto/-O0/-flto-partition=none/-ffat-lto-objects and gcc-8, gcc-9 or
> gcc-10, and the tentative fix for PR25700 (
> https://sourceware.org/pipermail/gdb-patches/2020-April/167451.html ), we run
> into this regression:
> ...
> (gdb) list x.adb:16, 16^M
> No source file named x.adb.^M
> (gdb) FAIL: gdb.ada/dgopt.exp: list x.adb:16, 16
> ...
> 
> The reason for the failure is that without the tentative fix for PR25700, we
> have an unshared psymtab:
> ...
>   { psymtab gdb.ada/dgopt/x.adb ((struct partial_symtab *) $hex)^M
>     readin no^M
>     fullname (null)^M
>     text addresses 0x0 -- 0x0^M
>     psymtabs_addrmap_supported yes^M
>     globals (none)^M
>     statics (none)^M
>     dependencies (none)^M
>   }^M
> ...
> and a shared psymtab (with user field set):
> ...
>   { psymtab gdb.ada/dgopt/x.adb ((struct partial_symtab *) $hex)^M
>     readin no^M
>     fullname (null)^M
>     text addresses 0x0 -- 0x0^M
>     psymtabs_addrmap_supported yes^M
>     globals (none)^M
>     statics (none)^M
>     user <artificial>@0x159a ((struct partial_symtab *) 0x37b57c0)^M
>     dependencies (none)^M
>   }^M
> ...
> 
> The tentative fix for PR25700 removes the unshared psymtab.
> 
> Then when trying to find a psymtab matching x.adb in
> psym_map_symtabs_matching_filename, we run into this continue for the shared
> psymtab:
> ...
>   for (partial_symtab *pst : require_partial_symbols (objfile, true))
>     {
>       /* We can skip shared psymtabs here, because any file name will be
>         attached to the unshared psymtab.  */
>       if (pst->user != NULL)
>        continue;
> ...
> and consequently cannot find the file.
> 
> Fix this by not skipping the shared symtab in
> psym_map_symtabs_matching_filename.
> 
> Build and reg-tested on x86_64-linux.
> 
> The test-case passes on master, starts failing with the tentative patch for
> PR25700, and passes again with this patch.
> 

Oops, now actually with test-case, and ChangeLog entries added.

OK for trunk?

Thanks,
- Tom


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